Process for producing a polyethylene-1,2-diphenoxyethane-4,4{40 -dicarboxylate

ABSTRACT

(in which R&#39;&#39; represents a di-valent aliphatic radical having one to four carbon atoms, or a di-valent aromatic radical and R&#39;&#39;&#39;&#39; is an aliphatic radical of one to four carbon atoms), m is an integer of one to four, P represents a numerical valence of the X radical and (4-m/P) is an integer of zero to three. A molded article obtained from said polymer has favorable mechanical properties, particularly a high Rockwell Hardness. Further, fibers obtained from said polymer possess a favorable tenacity, elongation, elastic recovery, boil shrinkage and maximum heat shrinkage stress.   A linear polyethylene-1,2-diphenoxylethane-4,4&#39;&#39;-dicarboxylate having a favorable heat-stability, whiteness and a high crystallization velocity capable of being die molded in a short time like &#39;&#39;&#39;&#39;Delrin&#39;&#39;&#39;&#39; is produced by reacting a 1,2-bis-paracarboalkoxy-phenoxyethane having an acid value of 0.03 or less with ethylene glycol in the presence of an ester interchange catalyst, such as a strontium or barium salt of mono-carboxylic acid having one to four carbon atoms or an orthoborate compound of the formula: Sr(B(OCH2CH2OH)(OR3&#39;&#39;&#39;&#39;&#39;&#39;)) 2 or Ba(B(OCH2CH2OH)(OR3&#39;&#39;&#39;&#39;&#39;&#39;)) 2 wherein R&#39;&#39;&#39;&#39;&#39;&#39; is selected from the group consisting of cyclohexyl, phenyl, cresyl and diphenyl, until methanol or longer evolves, and subsequently continuing the reaction until the desired degree of polymerization is attained at an elevated temperature under a reduced pressure in the presence of, as a polycondensation catalyst, an organotin compound having the formula RmSn X(4-m/P) wherein R is an aliphatic radical having one to four carbon atoms, a 3- to 6-membered alicyclic radical or an aromatic radical, X represents -R, -OR, -OH, SnR3,

nited States Patent llldehlko Kobayashi Tokyo; lilroshi Komoto, Saitama-ken; Masatsugu Yoshino, Saitama-ken, all of Japan [72] Inventors [21] Appl. No. 786,471

[22] Filed Dec. 23, 1968 [45] Patented Nov. 30, 1971 [73] Assignee Asahikasel Kogyo Kabushlki Kaisha Osaka, Japan [32] Priorities Dec. 27, 1967 [33] Japan Apr. 12, 1968, Japan, No. 43/241239 [54] PROCESS FOR PRODUCING A POLYETHYLENE- l,2-DIPHENOXYETHANEAA-DICARBOXYLATE 4 Claims, No Drawings [52] U.S. Cl 260/47 C, 260/40 R, 260/45.7 P, 260/473 G, 260/475 P, 260/606.5 B [51 Int. Cl ..C08g 17/013, C08g 17/015 [50] Field of Search 260/47 C, 475 P, 473 G [56] I References Cited UNITED STATES PATENTS 2,465,150 3/1949 Dickson ..260/47 (C) UX 2,503,251 4/1950 Edwards etal.. ..260/47 (C) UX 3,055,870 4/1962 Mclntyre et a1. 260/75 3,117,950 1/1964 Kibler et a1. 260/75 3,432,467 3/1969 Davies etal. 260/75 (N) X FOREIGN PATENTS 577,788 6/1959 Canada 260/75 UX 1,549,430 11/1968 France 260/47 C 579,462 8/1946 Great Britain 260/47 C 10/ 1 966 Great Britain 260/47 C OTHER REFERENCES Korshak Polyesters, published, New York, N.Y., 1965, Pergamon Press, QD341E7K63 pp. 153 & 154

Korshak Polyesters, published, New York. N.Y., 1965. Pergamon Press. pp. 34, 65- 67, 143, 149 & 151

Primary Examiner-William M. Short Assistant Examiner- Louise P. Quast Almrne \---Waters, Roditi, Schwartz and Nissen ABSTRACT: A linear polyethylene-1.Z-diphenoxylethane- 4.4'-dicarboxylate having a favorable heat-stability, whiteness and a high crystallization velocity capable of being die molded in a short time like D elrin" is produced by reacting a 1,2-bispara-carboalkoxy-phenoxyethane having an acid value of 0.03 or less with ethylene glycol in the presence of an ester interchange catalyst, such as a strontium or barium salt of mono-carboxylic acid having one to four carbon atoms or an orthoborate compound of the formula: Sr[B(OCl-1 CH,OH)(OR,,"] 2 or Ba[B(OCH,CH 0H)(OR 2 wherein R is selected from the group consisting ofcyclohexyl, phenyl, cresyl and diphenyl. until methanol or longer evolves, and subsequently continuing the reaction until the desired degree of polymerization is attained at an elevated temperature under a reduced pressure in the presence of, as a polycondensation catalyst, an organotin compound having the formula m H mIP) wherein R is an aliphatic radical having one to four carbon atoms, a 3- to 6-membered alicyclic radical or an aromatic radical, X represents R, OR, OH, SnR

(in which R represents a di-valent aliphatic radical having one to four carbon atoms, or a di-valent aromatic radical and R" is an aliphatic radical of one to four carbon atoms), m is an integer of one to four, P represents a numerical valence of the X radical and (4-m/P) is an integer of zero to three. A molded article obtained from said polymer has favorable mechanical properties, particularly a high Rockwell Hardness. Further, fibers obtained from said polymer possess a favorable tenacity, elongation, elastic recovery, boil shrinkage and maximum heat shrinkage stress.

More particularly, the

PROCESS FOR PRODUCING A POLYETHYLENE- l .2- DIPHENOXYETHANE-4,4-DICARBOXYLATE present invention relates to a process for producing a straight chain polyethylene-1,2-diphenoxyethane-4,4'-dicarboxylate having a favorable heat-stability, whiteness and a high crystallization velocity, which comprises effecting an ester interchange reaction and subsequent polycondensation reaction of l,2-bis-para-carboalkoxyphenoxyethane with ethylene glycol in the presence of a combined catalyst capable of producing said polymer. Even more particularly, the present invention relates to a process for producing a straight chain polyethylenel ,2 -diphenoxyethane- 4,4-dicarboxylate, which comprises effecting an ester interchange reaction of l,2-bis-para-carboalkoxy-phenoxyethane with ethylene glycol in the presence of a specific barium or strontium compound as an ester interchange catalyst, and subsequently subjecting the resultant reaction product to a polycondensation reaction in the presence of a specific organotin compound as a polycondensation catalyst. Polymer thus obtained is characterized in that a crystallization velocity is markedly high as compared with those of products prepared in accordance with the prior known processes and that an isothermal crystallization half-life time at 222 C. is l'35"or less.

It has been known that a molded article of polyethylenel ,2- diphenoxyethane-4,4'-dicarboxylate has a high initial Young's modulus, excellent alkali resistant hydrolyzing characteristic and favorable dimensional stability as compared with that of polyethylene terephthalate. However, such molded article has longer molding interval than Delrin (Trade name of polyoxymethylene manufactured by du Pont).

Further, in a field of synthetic fibers, only the fiber has been obtained therefrom which had a low boil shrinkage of 2 percent or less, an extremely small heat shrinkage stress and a bad elastic recovery. These fibers have not been preferred in general for use as cloths due to drawbacks such as ruffled appearance of cloths, a bad crease proofness and so on.

Furthermore in a field of films, transparent and tough films have been produced therefrom by a biaxial stretching. However, in the detailed investigation of physical properties thereof, it has been found that these films have drawbacks such as a large residual elongation, small strength and in sufficient dimensional stability. To overcome these drawbacks, a contrivance was made by applying a uniaxial stretching process to said film. However, an application of hot-stretching to a suddenly cooled unstretched film only resulted in an insufficient strength in transverse direction and a readiness in fibrillation by heating.

Originally, in fields of synthetic fibers, films and resins, excellencies in mechanical strength and other physical properties are not all for a requirement for the molded article, but superior whiteness and heat-stability should be provided. These specific properties have been particularly required in the fields of synthetic fibers and films.

0n the other hand, it has been known from the specification of U.S. Pat. No. 2,720,507 that a high molecular weight polymer is produced by an ester interchange reaction and a subsequent polycondensation reaction from a low alkyl ester of an aromatic dibasic acid and glycol in the presence of an organotin compound as a catalyst for both the reactions. However, said process has been unable to apply with a favorable result to the production of polymer which is intended by the present invention. in particular, the polymer obtained in accordance with said process has brought about a low melting point, marked coloring and low crystallization velocity thereto.

The object of the present invention is to provide a straight chain polyethylene-1,2-diphenoxyethane-4,4'-dicarboxylate having a favorable heat-stability, whiteness and a high crystallization velocity, which comprises at least percent by weight or more of repeating units in a molecular chain having the structure of Another object of the present invention is to provide a process for producing a straight chain polyethylene-1,2- diphenoxyethane-4,4'-dicarboxylate, which comprises effecting an ester interchange reaction of l,2-bis-para-carboalkoxyphenoxyethane with ethylene glycol in the presence of a specific barium or strontium compound as a ester interchange catalyst, and subsequently subjecting the resultant reaction product to a polycondensation reaction in the presence of a specific organotin compound as a polycondensation catalyst, said produced polymer being characterized in that a crystallization velocity is markedly high as compared with those of products prepared in accordance with the prior known processes and that an isothermal crystallization half-life time at 222 C. is 1 foot 35 inches or less.

These and other objects of the present invention will become apparent to those skilled in the art from a consideration of the following specification and claim.

In accordance with the present invention, it has been found that polyethylene-l,2-diphenoxyethane-4,4'-dicarboxylate is produced by subjecting l,Z-biS-para-carboalkoxy-phenoxyethane and ethylene glycol to an ester interchange reaction in the presence, as a ester interchange catalyst, of a specific barium or strontium salt soluble in the reaction mixture and subsequently the resultant reaction product to a polycondensation reaction in an addition just before said polycondensation, as a polycondensation catalyst, of a specific organotin compound.

The polyethylene-l ,2-diphenoxyethane-4,4'-dicarboxylate obtained in accordance with the present invention is characterized by having a favorable heat-stability, whiteness and a high crystallization velocity.

The ester interchange catalyst used for attaining sufficient effects in the practice of the present invention includes a strontium salt and a barium salt of a monocarboxylic acid having one to four carbon atoms such as acetic acid, propionic acid, butyric acid and the like as well as a strontium salt and a barium salt of an orthoborate. Salts of the other metals such as manganese, lead, calcium, magnesium and the like or an organotin compound cannot be used as the ester interchange catalyst in the present invention, since the polymer to be produced by the subsequent polycondensation reaction in the presence of the specific organotin compound is poor in the heat-stability and low in the crystallization velocity.

Said orthoborates used in the form of strontium salt or barium salt as the ester interchange catalyst in the present invention include an ester of boric acid having an aliphatic or aromatic radical, such as ortho-cyclohexylborate, ortho-phenylborate, ortho-cresylborate, ortho-diphenylborate and the like. Said orthoborate compound has the formula Ba[ B(OCH CH OH )(OR;, )12 wherein R' is selected from the group consisting of cyclohexyl, phenyl, cresyl and diphenyl. The strontium or barium salts of said orthoborates are prepared by heating with stirring a glycolate of strontium or barium and the foregoing orthoborate at a molar ratio of 1:2 respectively in an inert solvent such as toluene, xylene, dioxane and the like or in ethylene glycol at a temperature of to 250 C. for l to 2 hours. Said ester interchange catalyst is used in an amount of 0.005 to 0.5 percent by weight, preferably 0.0lto 0.2 percent by weight, based on a polymer to be produced.

The organotin compounds used in effecting the present invention are represented by the formula:

R,,,SN X4-m/p) wherein R is an aliphatic radical having one to four carbon atoms, a 3- to 6-membered alicyclic radical or an aromatic radical, X is R, OR, OH, -SnR a halogen, 0 or Trimethyl-tin-acetate, tricyclohexyl-tin-acetate, dibutyl-tin-acetate, 7i R,,,SnY (Y is a halogen.) Dibutyl-tin-dichloride, dibutyl-tin-dibromide,

ll R SnO(|J W RV Diphenyl-tin-maleate dimethyl-tin-phthalate Said organotin compounds are used in an amount of 0.005 to 0.1 percent by weight, preferably 0.01 to 0.05 percent by weight, based on polymer to be produced.

TABLE I.ISOTHE RMAL The l,2-bis-para-carbomethoxy-phenoxyethane used in the present invention should be that having an acid value of 0.03 or less. The acid value is measured by titrating with O.lN or KOH and phenol phthalein an acid component of the solution which is prepared by dissolving with heating 1 g. of l,2-bispara-carb0alkoxy-phenoxy-ethane in g. of ethyl alcohol. Such acid value cannot be attained satisfactorily by only a few rounds of recrystallization from solvent, for instance. recrystallized from toluene which is ordinarily used. A number of rounds of recrystallization is required to obtain such high purity as 0.03 or less acid value. If the acid value is more than 0.03, the polymer obtained is poor in heat-stability. The reason of said result is not clear, but a cause thereof may be a mixing of a slight amount of impurities at the time when 1,2- bis-para-carboalkoxy-phenoxyethane is produced. The purification by distillation of l,2-bis-para-carboalkoxy-phenoxyethane can also be effected in an usually known manner. In preferable, by carrying out the distillation in an addition in the order of 0.01 to 0.1 percent by weight, based on the above l,Z-bis-para-carboxyalkoxy-phenoxyethane, of a manganese, calcium, magnesium or sodium salt of phosphoric acid, phosphorous acid or the like, an oxide such as manganese oxide, calcium oxide, magnesium oxide, sodium oxide or the like, or a metal such as manganese, calcium, magnesium, sodium or the like, the distillate therefrom is improved in the whiteness and lowered in the acid value.

The ester interchange reaction in the present invention is carried out by adding to the 1,2-bispara-carboalkoxy-phenoxyethane purified in accordance with the foregoing procedures 1.3 to 5.0 mole times ofethylene glycol. The resultant mixture is heated at a temperature in the range of to 240 C. until methanol no longer evolutes.

The polycondensation reaction in the present invention is effected by heating the reaction product obtained in the above ester interchange reaction at a temperature in the range of 240 to 300 C., preferably in the range of 260 to 280 C., under a reduced pressure of 10 mm. Hg. or less with evolution of the ethylene glycol. 1n the course of the polycondensation reaction, titan oxide as a flatting agent and a phosphorus compound such as phosphoric acid, phosphorous acid, triphenyl phosphite and the like as a coloring stabilizer may be added.

The polymer produced in accordance with the present invention can be molded in a die at a low temperature less than 70 C. The resultant molded article shows excellencies in quality, stability and mechanical properties, in particular in Rockwell Hardness. Further, an use of the present polymer makes it possible to shorten the molding interval in a die molding. For instance, it is possible to carry out the molding in a CRYSTALLIZA'IION HALF-LIFE TIME Pre-determined constant Catalyst temperature, C.

Number Ester interchange Polycondensation 222 227 232 Example:

1 Sr (OAc) Bu SnO 1'30" 3'23" BD(OAC)1 Bu1Sn(OMe) 1'34" 3'21" 10'00" Sr(OAc); BIIQSnO 1'32" 3'30" ..l.. Sr(OAc)i Me;Sn(OI1) 1'32" 3'27" 10'03" 5 Ba(OAc) B117S11(OA0)1 1'30" 3'20" 6 Sr|:B(OCHCH1OH)(O);]; BuiSnO 1'27" 3'10" 10'00" 7 BB[B(OCH1CHzOI'I)(O) ]z BuSn(0Me)1 1'20 305" 8 Sr[B(O CH;CH;0H)(O@)3]1 Bu1(0Ac)z 1'10 3'08" Cu(OAc) BmSnO 4'33" 1057 ZntOAch Sb203 3'15" 5'48" Comparative Example 1. Mn(0Ac)1 SbzOg 2'32" 7'39" 16'00" Pb(OAC)z Sb20a 3'39" 6'48" 1900" Mn(OA0)2 BtlzSnO 6'32" 15'21" 50'21" Reference Experiment:

1 Zn(OAc), 0'35" 17'22" 51'35" 2 BmSnO r 8'25" 18'35" 50-23" time as long as that of Delrin.

As the result of measuring the crystallization velocity of the polymer capable of giving such favorable molded article, the present inventors have found that an isothermal crystallization lization velocity appears. A value of the reduced viscosity of the polymer favorable in a processability and excellent in a mechanical strength required for an ordinary molded article is in the range of 0.7 to 1.0, whereby a favorable crystallization half-lifetime of the polymer is '35 'or less at 222 C. 5 velocity as shown in Table 1 is given The isothermal crystallization half-life time referred to Fibers obtained by i take up method using the polymer herem throughfmt thePl'esem specification Shows f produced in accordance with the present invention show a crystalhzauo" Velocity 1S deflned as P f favorable tenacity, elongation, elastic recovery, boil shrinkage the l 'yf l f g"? cryslalmzed h and maximum heat shrinkage stress even at a reeling velocity z ig gg gel z ggfi i glgfr ggc l 23 t ggsi c g g of 2000 m./min. Further, by usual spinning andstretching a 9' method, fibers having high elastic recovery, boil shrinkage and minutes, then the temperature is lowered to a predetermined maximum heat Shrinkage stress can also be obtained constant temperature, for example 222 C., at a veloclty of 6 Table III shows a relation of boil shrinkage, elastic recovery and maximum heat shrinka e stress. The sam le was re ared g P P P Table I shows variations in isothermal crystallization halfby spinning a polyme at a sp n g temperature of 295 a life time of polymers obtained by various combinations of an extruding linear velocity of l7 m-/minand a! a feeling catalysts used. velocity of i000 m./min., and hot-stretching the resultant un- TABLE II Isothermal crystallize Ester Percent Polyconden- Percent Reduced tion half Rockwell Molding interchange by satlon by viscosity life time Hardness interval catalyst weight catalyst weight nsp/c at 222 C. (M scale) (second) Example:

1 Sr(OAc) 0.08 Bmsno 0. 03 0.717 130" 101 65 Ba(OAc), 0.09 Bu,Sn(0Me) 0.03 0.949 134 100 65 Comparative Example 1. Zn(OAc) 0.03 Sb 03 0. 03 0.827 315" 91 130 CB OAC 3 0. 06 G60; 0.01 0.892 7'18" 80 120 Reference Experiment Mg(OAc) 0.05 S13 0; 0.03 0.825 212" 92 100 Ba(OAc); 0.09 GeO, 0.01 0. 923 1'48" 92 so MH(OAC)2 0. 04 BuzSnO 0. 03 0. 668 5'20 00 130 TABLE lll stretched filament by 3 times at 140 C. The heat shrinkage stress was measured in air at C. under no tension at a temperature rising velocity of 1 C./min. in accordance with the Elasicwmethod of Dr. Kamide [Journal of Fiber institute, 22, 249 when mx'mum (1966)]. The elastic recovery when elongated was measured Boil elongated shrinkage by elongating the sample to a definite elongation (for examhrink g y 5% stress pie, 5 percent) at an elongation velocity of 10 percent/min, (g'lcm'xxwdl and after holding the elongated sample for one minute, 40 recovering towards the original state at the same rate as in the Emmple elongation. Said elongation and recovery were measured ExnmpleZ 4.2 90 7.6 l f 1 Th 1 d th compamivc aong an axis 0 e ongation. e p0 ymers use were ose Example 1 1.3 43 us listed in table ll. Refewynve 40 M A tough film or tape which can not be fibrillated can be Expenmum l 5 42 I 6 45 produced by extruding the polymer obtained in accordance 1;, M with the present invention in a molten state to a film or tape, I passing the resultant film or tape without a sudden cooling 0 O o 0 Table ll shows a relation between an isothermal crystallizathrough a Zone heated at Q to 150 to Set a crystallization o degree defined from a density of unstretched film or tape at 7 half-me at 222 of polymers produced m the to 35 ercent and then stretchin uniaxiall the resultant film presence of various combinations of catalysts and Rockwell or ta 2 g y Hardnesses or resins molded in a die at 70 C. p

. The following examples are given as illustrative of the Said molding was carried out by extruding a polymer by present invention and are not to be considered as limiting. The means of a screw type extruder at a cylinder temperature of f th 1 th [es is sh w the 270 C. under a pressure of 500 kg./cm. for an injection time "2 9 p0 "l 3 23 6 f of 20 seconds to a die heated at 70 C. A time required for one lvlscosny. (nsp' f d f Ion cycle inclusive of enough cooling time to complete the crystal- I S gr i m a 3" il lization was shown as molding interval in table II. A viscosity 6 F orloe m m 3 0 an pa are y of polymer referred to in said table II shows a reduced viscosiwelg un e55 o erwlse spec 1e a ty at 35 C. of 1 percent solution of the polymer in a mixed sol- EXAMPLE l vent of tetra-chloroethane and phenol at a ratio by weight of 3:1 respectively. 1,2-bis-para-carbomethoxy-phenoxyethane is purified by It has been found from table II that the polymer having a adding 0.] part of manganese phosphate to I00 parts of a higher crystallization velocity in the range less than l35"of crude l,2-bis-para-carbomethoxy-phenoxyethane and subthe crystallization half-life time at 222 C. possesses a short jecting the resultant mixture to a purification by distillation at molding interval and favorable mechanical properties. 230 C. under a reduced pressure of 1 mm. Hg. to solidify. To

The reduced viscosity of the polymer produced in ac- 100 parts of purified product was added 75 parts of ethylene I cordance with the present invention may be of a value more glycol and 0.09 part of strontium acetate as an ester inthan that required at a processing of an ordinary molding. ln terchange catalyst, and subjected to an ester interchange reacthe case where the reduced viscosity is 0.6 or less, the crystaltion at 220 C. for 4 hours with evolution of methanol. Then to lization velocity becomes higher than those of values of the the resultant reaction product was added 0.1 part of triphenpolymers produced in accordance with the present invention y p p 35 a colormg stabilize! and l 0f 4 9): listed in table 1, which results in a decrease in a mechanical $110 as a polycondensation catalyst, and heated at 280 C. for strength of molded article obtained. When the reduced 3 hours under a reduced pressure of 0.l mm. Hg. or less with viscosity becomes to be 0.6 or more, a decrease in the crystalevolution of ethylene glycol. The resultant polymer was a solid having a reduced viscosity of 0.717, a whiteness of class five and a melting point of 250 C. Said polymer was not colored even heated in air at 240 C. for 3 hours.

EXAMPLE 2 100 Parts of crude l,Z-bis-para-carbomethoxy-phenoxyethane subjected to a purification by distillation by the addition of 01 part of sodium metal and 80 parts of ethylene glycol were charged to an ester interchange vessel. 0.09 Part of barium acetate as an ester interchange catalyst was added thereto and heated at 220 C. for 4 hours with evolution of methanol. Then the resultant reaction product was transferred to a polycondensation vessel. 0.1 Part of tripheny phosphite as a stabilizer and 0.03 part of dibutyl-tin-dimethoxide were added thereto and heated at 280 C. under a reduced pressure of 0.1 mm.I-Ig or less with evolution of ethylene glycol. The resultant polymer was a solid having a reduced viscosity of 0.949, a melting point of 249 C. and a whiteness of class 5, and was not colored even heated in air at 240 C. for 3 hours.

COMPARATIVE EXAMPLE 1 Polymerizations were carried out in the same manner as in Example 1 but using calcium, manganese, magnesium, lead or zinc acetate as an ester interchange catalyst and Bu SnO or Sb O as a polycondensation catalyst. The results are shown in table IV.

l but using l,2-bis-para-carbomethoxy-phenoxyethane which had an acid value of 0.02 after 10 rounds of recrystallization from toluene. There was obtained a white solid having a whiteness of class 5, a good transparency and a melting point of 249 C. No coloring took place even heated at 240 C. for 3 hours.

EXAMPLE 4 Reaction was eficcted in the same manner as in example I but replacing dibutyl-tin-oxide with trimethyl-tin-hydroxide. There was obtained a white solid having a whiteness of class 5, a good transparency and a melting point of 248 C. No coloring took place even heated at 240 C. for 3 hours.

EXAMPLE 5 EXAMPLE 6 Reactions were effected in the same manner as in example l but replacing strontium acetate with 0.2 part of strontium salt of ortho-cyclohexylborate TABLE IV.-A RELATION BETWEEN AN ESTER INTERCHANGE-POLYCONDENSATION CATALYST COM- BINATION AND A HEAT-COLOURING Ester interchange catalyst Ca(OAc); Mn(0Ac)z Mg(OAc) Pb(OAc) ZII(OAO)2 Ba(OAc) Sr(0Ac)z Polycondensation catalyst (0.06) (0.04) (0.07) (0. 04) (0.03) (0.09) (0.08)

1 /0 0.784 1.037 0.825 0.825 0.827 0.854 0.934. Sbz0 (0.03) Transparcnoy Good Good G d Heat-colouring XX XX whiteness 3 3 1/ 1111 81100103)..." Transparency...

Tm whiteness 4 4 4 3 3 5 5- The transparency was determined bad" for a polymer where there was a cloud in a breaker plate after spun, while good" for a polymer where there was utterly no cloud therein.

The heat-coloring was determined as for a polymer where there was utterly no change in color when heated in air at 240 C. for 3 hours, as xx for a polymer where there was a coloring and as COMPARATIVE EXAMPLE 2 Reactions were effected in the same manner as in example I but using l,2-bis-para-carbomethoxy-phenoxyethane which had an acid value of 0.08 and was twice recrystallized from toluene. There was obtained a solid having a whiteness of class 4, a bad transparency and a melting point of 248 C. A heatcoloring ,was xx.

EXAMPLE 3 Reactions were effected in the same manner as in Example sr[a oomomom(o@) 3 1 There was obtained a solid having a melting point of 250 C., a 'rpsp./c. of 0.798 and a whiteness of class 5. No coloring took place even heated in air at 240 C. for 3 hours.

EXAMPLE 7 Reactions were effected in the same manner as in Example 2 but replacing barium acetate with 0.25 part of barium salt of ortho-phenylborate There was obtained a solid having a melting point of 249 C.. a nsp./c. of 0.825 and a whiteness of class 5. No coloring took place even heated in air at 240 C. for 3 hours.

COMPARATIVE EXAMPLE 3 Reactions were effected in the same manner as in example 7 but using l,2bis-para-carbomethoxy-phenoxyethane which had an acid value of 0.08 and was recrystallized from toluene. There was obtained a solid having a whiteness of class 4, a bid transparency and a melting point of 249 C. A heat coloring was xx.

EXAMPLE 8 Reactions were effected in the same manner as in example 6 but replacing dibutyl-tin-oxide with dibutyl-tin-diacetate. There was obtained a white solid having a 'nspJc. of 0.982, a whiteness of class 5, a good transparency and a melting point of 249 C. A heat-coloring was EXAMPLE 9 Reactions were effected in the same manner as in example 7, but replacing dibutyl-tin-methoxide with trialkyl-tinhydroxide. There was obtained a white solid having a nspJc. of 0.932, a whiteness of class 5, a good transparency and a melting point of 250 C. A heat-coloring was EXAMPLE The polymer obtained in accordance with example 9 was extruded at 310 C. at an extruding velocity of 0.5 g./min. and was reeled at a velocity of 2000 m./min. The resultant fibers had a tenacity of 3.5 g./d., an elongation of 56.4 percent, an index of refraction An=0. 161, a density of 1.363 g./cm., a boil shrinkage of 3.5 percent and a maximum heat shrinkage stress of 7.5 g./cm. X10.

EXAMPLE 1 l The polymer obtained in accordance with example 2 was extruded into air zone heated at 1 10 C. by an extruder having a dieround of 40 mm. in diameter, a dieslit of 350 mm. long and 0.5 mm. wide at a die temperature of 280 C., and reeled at a reeling velocity of 5 m./min. to prepare an unstretched film having a thickness of 100 microns and a crystallization degree of percent. Stretching the resultant film by 4.0 times at 120 C, without being cut, there was obtained a film which was not fibrillated and has a yielding strength of 2690' kg/cmF, an elongation of 6.4 percent, a. Young's modulus of 80,000 kg./cm. and a heat shrinkage at 180 C. for one minute of 1 percent or less.

EXAMPLE 12 The polymer obtained in accordance with example 2 was extruded by a screw type extruder at a cylinder temperature of 270 C. under an extruding pressure of 500 kg./cm. for an injection time of seconds to a die kept at a low temperature of 70 C. A required time for one cycle inclusive of a cooling time of molded article obtained was favorable The molded article had a yielding strength of 820 kg./cm. an elongation of 6 percent, a breaking strength of 5 l 3 kg./cm. a breaking elongation of 22 percent, a modulus of elasticity of 2.57Xl0 kg./cm., a Rockwell Hardness of 100, a density of 1.35 g./cc., a thermal deformation temperature of 91 C. and a water content of 0.04 percent.

The invention being thus described, it will be obvious that the same way be varied in many ways. Such variation are not to be regarded as a departure from the spirit and scope of the present invention, and all such modifications are intended to be included within the scope of the following claim.

What we claim is:

l. A process for producing a moldable straight chain polyethylenel ,2-diphenoxyethane-4,4'-dicarboxylate having a favorable heat-stability, whiteness and a high crystallization velocity, which comprises reacting a l,2-bis-para-carboalkoxyphenoxyethane having an acid value of 0.03 or less with ethylene glycol in the presence of 0.005 to 0.5 percent by weight based on the polymer to be produced of at least one ester interchange catalyst selected from the group consisting of a strontium salt of a monocarboxylic acid having one to four carbon atoms, a barium salt of a monocarboxylic acid having one to four carbon atoms, and an orthoborate compound of the formula wherein R' is selected m/p)the group consisting of cyclohexyl, phenyl, cresyl and diphenyl, until methanol no longer evolves, and subsequently subjecting the resultant reaction product to a polycondensation reaction with evolution of ethylene glycol in the presence of 0.005 to 0.1 percent by weight, based on the polymer to be produced of a polycondensation catalyst which is an organotin compound of the formula:

R SnX,4 m/p) wherein R is an aliphatic radical having one to four carbon atoms, a 3-- to 6- membered alicyclic radical or an aromatic radical, X is -11, OR, --OH, SnR

a halogen, O or in which R is as defined above, R" is an aliphatic radical of one to four carbon atoms and R is a -CH CH radical or a phenylene radical, m is an integer of one to four, p is the numerical valence of the X radical and (4 m/p) is an integer of zero to three.

2. A process according to claim 1, wherein said ester intefchange reaction is effected at a temperature in the range of to 240 C.

3. A process according to claim 1, wherein said polycondensation reaction is effected at a temperature in the range of 240 to 300 C. under a reduced pressure of 10 mmllg or less.

4. A process according to claim 1, wherein said monocarboxylic acid having one to four carbon atoms is acetic acid, propionic acid or butyric acid.

i i l l i UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3, 3 Dated November 30, 1971 Inventor) Hidehiko Kobayaahi et a1 It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

On the cover sheet [73} in the assignee': name "Asahikaaei" should read Asahi Kasei Signed and sealed this 12th day of December 1972.

(SEAL) Atteet:

ROBERT GOTTSCHALK EDWARD M.FLETCHER,JR.

Commissioner of Patents Attesting Officer RM USCOMM-DC 60376-P69 9 U5 GOVERNMENT FIINYING OFFICE: 1569 0-366-334. 

2. A process according to claim 1, wherein said ester interchange reaction is effected at a temperature in the range of 150* to 240* C.
 3. A process according to claim 1, wherein said polycondensation reaction is effected at a temperature in the range of 240* to 300* C. under a reduced pressure of 10 mm.Hg or less.
 4. A process according to claim 1, wherein said monocarboxylic acid having one to four carbon atoms is acetic acid, propionic acid or butyric acid. 